British advise against one expensive fertility treatment used here

The British Fertility Society just released guidelines advising patients against Preimplantation Genetic Diagnosis (PGD), an expensive embryo screening procedure that doctors first hoped would increase the odds of fertility treatments. But, the society reports, it's turning out that there's no evidence PGD either improves pregnancy rates or decreases miscarriages. So lots of prospective parents may be paying the $2,500 to $5,000 the procedure costs even though it isn't helping them.

In the United States, we don't have any such society that oversees fertility treatments. We have the American Society of Reproductive Medicine, which tells its members what the official policy is, but decides what's ethical but doesn't ban procedures. At its conference last October, it decided the same thing about PGD.

"The use of preimplantation genetic screening for chromosomal problems may one day become an essential component of infertility therapy, but for now, available evidence does not support its effectiveness and common usage," Dr. Steven J. Ory, president of ASRM, said in the report.Here's how PGD works: Doctors can perform PGD on embryos growing in the lab after in vitro fertilization. They take one cell from an eight-cell embryo and send it off to the lab. As far as anyone knows, it doesn't hurt embryos that grow into babies, but it may end up killing off some embryos.

There can be a lot of hysteria surrounding the procedure, as if couples were going through all this just to produce a "designer baby." In reality, two kinds of couples even consider this and you wouldn't want to be in either of their positions. One is the family with a serious, often deadly, genetic disease. They use a variant called Preimplantation Genentic Screening that looks for a specific disease. The other are couples with a history of failed IVF cycles or pregnancies. They're not looking for perfect babies, just ones that will survive.

In the United States many doctors advise against the procedure for the same reasons that the British did. But others are still selling it and still believe in it. The Center for Preimplantation Genetics says that it "improves chances for successful pregnancy and birth." The Fertility Institute says that PGD will "dramatically improve the chance of successful IVF." The California Pacific Medical Center in San Francisco lays out possible benefits and risks.